To manufacture a semiconductor device, a treatment subject such as a semiconductor wafer or a liquid-crystal display panel glass substrate is desired to have a highly-cleaned surface, and therefore a wet treatment is performed on the surface of the treatment subject by using various methods. The wet treatment methods can be broadly classified into a batch type or one-bath type in which a plurality of treatment subjects are simultaneously treated and a single-wafer type in which treatment subjects are treated one by one. In the batch-type treatment, one treatment bath is provided for one treatment chemical solution, and a batch formed of a plurality of treatment subjects are sequentially immersed into each treatment bath for continuous treatment. In the one-bath treatment method, a batch is put into a treatment bath, and injection and discharge of treatment chemical solutions to and from the same treatment bath is repeated to perform treatment. By contrast, in the single-wafer treatment, a treatment chemical solution is supplied for each treatment subject for treatment, and a treatment effect higher than that of the batch-type and one-bath type cleaning can be obtained.
Conventionally, a treatment subject is treated by a batch-type or one-bath-type treatment device excellent in mass production to reduce particles and metal impurities. However, in recent years, with an increase in diameter of the treatment subject and increasing desires for a high degree of cleaning of the surface of the treatment subject after treatment, the single-wafer treatment device, which can obtain a higher treatment effect, has become often used.
As a single-wafer treatment device, there is a rotary treatment device which treats the surface of a treatment subject by supplying a treatment chemical solution while rotating the treatment subject. The treatment device as described above includes a holding member which rotates while holding the treatment subject inside a treatment chamber, and supplies a treatment fluid from a nozzle provided to an upper portion of the treatment chamber to the rotating treatment subject to treat the surface of the treatment subject. The treatment fluid supplied to the surface of the treatment subject goes over the entire surface of the treatment subject by a centrifugal force associated with the rotation of the treatment subject, and is shaken off to the outside and scattered after the surface is treated. Thus, a cup for collecting the scattered treatment fluid is provided on the periphery of the holding member which rotates while holding the treatment subject, and a discharge pipe for discharging the collected treatment fluid to the outside of the treatment chamber is connected to a bottom portion of the cup. Also, during the treatment, clean air is supplied from outside to the inside of the treatment chamber, and the air is discharged to the outside of the treatment chamber from the exhaust pipe provided on a bottom wall of the cup via a gap between the holding member and the cup to discharge vaporized gas or mist of the treatment fluid present inside the cup, thereby preventing particles from being attached to the surface of the treatment subject.
As a treatment fluid in the treatment as described above, an acidic chemical solution, an alkaline chemical solution, an organic solvent, and the like are used, and a treatment chemical solution according to the treatment is selectively supplied to the treatment subject. In this case, the treatment fluids of different types are sequentially supplied to the treatment subject held by the holding member. For example, when an acidic chemical solution is supplied first, an alkaline chemical solution is supplied second, and then an organic solvent is supplied third, exhaust of each treatment fluid is required to be treated in each different exhaust treatment facility. Thus, in the treatment device as described above, exhaust is performed from the treatment chamber via a common exhaust pipe, and then the common exhaust pipe is branched into individual exhaust pipes for the respective treatment fluids discharged from the treatment chamber, thereby allowing the vaporized gas and mist of the treatment fluids discharged from the treatment chamber to be guided to an exhaust treatment facility corresponding to each treatment fluid.
Since the single-wafer treatment device can treat only one treatment subject at one time, the treatment capability per unit time for each treatment device is lower than that of the batch-type treatment device or the like. Thus, a plurality of treatment devices are collectively installed, and a treatment subject is delivered to the treatment chamber of each treatment device by using a common delivery mechanism to perform a concurrent treatment on a plurality of treatment subjects, thereby improving the treatment capability per unit time.
In the treatment device as described above, each individual exhaust pipe branched from the common exhaust pipe of the treatment chamber is connected to a collective exhaust pipe for each same treatment fluid on a downstream side, and a downstream end of this collective exhaust pipe is guided to an exhaust treatment facility applicable for each treatment fluid. Also, each individual exhaust pipe branched from the common exhaust pipe of the treatment chamber is provided with valves, which are opened and closed so as to correspond to the types of treatment fluid supplied to the treatment chamber. For example, when a treatment is performed with an acidic chemical solution, only a valve of the individual exhaust pipe for discharging vaporized gas or mist of the acidic chemical solution is opened, and a valve of the individual exhaust pipe for discharging vaporized gas or mist of other treatment fluids is closed.
Also, in the treatment device as described above, treatments with the same treatment fluid are not necessarily performed in all treatment chambers in synchronization with each other, and it is often the case that different treatments are performed in different treatment chambers. For example, a treatment with an acidic chemical solution is performed in one treatment chamber, a treatment with an alkaline chemical solution is performed in another treatment chamber, and a treatment with an organic solvent is performed in still another treatment chamber. By contrast, since the exhaust amount of the collective exhaust pipe connected to the individual exhaust pipe from each treatment chamber is constant, if the number of treatment chambers communicating with the collective exhaust pipe is changed by opening and closing the valve of the individual exhaust pipe connected to each treatment chamber according to the treatment, the exhaust pressure inside the treatment chamber communicating with the collective exhaust pipe fluctuates.
That is, if the number of treatment chambers communicating with the collective exhaust pipe is decreased, the exhaust pressure inside the treatment chamber communicating with the collective exhaust pipe is increased. If the number of treatment chambers communicating with the collective exhaust pipe is increased, the exhaust pressure inside the treatment chamber communicating with the collective exhaust pipe is decreased. In a conventional treatment device, with these fluctuations in exhaust pressure inside the treatment chamber, there is a problem in which discharge of vaporized gas or mist inside the treatment chamber is insufficient to cause particles to be attached to the surface of the treatment subject. To address this problem, a substrate treatment device of Patent Literature 1 has been suggested.
The above-mentioned literature describes the substrate treatment device in which great fluctuations in exhaust pressure due to the treatment situation in one treatment chamber can be prevented in other treatment chambers and attachment of particles to a wafer associated with fluctuations in exhaust pressure can be inhibited.
In this substrate treatment device, exhaust from a treatment chamber is guided by a common exhaust pipe to an exhaust induction chamber, and is branched via the exhaust induction chamber to each individual exhaust pipe. The exhaust induction chamber is connected via a continuous hole to each individual exhaust pipe. With rotation of a rotating member having an continuous hole provided inside the exhaust induction chamber, a continuous hole communicating with one of the individual exhaust pipes is opened to cause an exhaust communication chamber and the individual exhaust pipe to communicate with each other. Also, each individual exhaust pipe has an open port separately from a communication port with the exhaust communication chamber. By an interrupting member rotating together with the rotating member, the open port of an individual exhaust pipe communicating with the exhaust communication chamber is closed and the open port of an individual exhaust pipe not communicating with the exhaust communication chamber is opened. By introducing air from the opened open port and supplying outside air to the collective exhaust pipe, large fluctuations in exhaust pressure inside another treatment chamber are prevented.